It has long been a need of the art to provide machinery and methods for the rapid, economical and efficient filling of containers such as bottles or cans with carbonated liquids. It will be appreciated that such carbonated liquids present problems in filling as they must be filled under pressure in order that the carbonation cannot escape from the liquid during the filling operation. The carbonation must then be securely contained in the can by an immediately affixed end or, in a bottle, by a cap of either the screw-on or crimped-on type, the latter being referred to hereinafter as a "crown".
Machinery and methods for the filling of containers with carbonated liquids have generally evolved into counterpressure filling machines in which the container is first filled with a gas under pressure, e.g., CO.sub.2 at 40 psi; thereafter the carbonated liquid is admitted to the bottle. Since the bottle is already under pressure, the carbonation does not escape, and if the container is closed very quickly thereafter, the carbonation is retained in the liquid. However, prior art valves and machinery for the filling of bottles and cans with carbonated liquids have been more complex and bulky than is desirable and, accordingly, a need continues in the art for improvement on such machines. For example, a filling valve use in a carbonated liquid bottling machine is shown in U.S. Pat. No. 4,089,353 to Antonelli. In that patent, a filling valve is shown which connects a bottle to be filled with a tank containing a supply of liquid with which the bottle is to be filled, and of the pressurized gas for counterpressurizing. The valve is controlled by cam means communicating with the outside of the tank for actuation such that the gas is first admitted to the bottle. The bottle is filled with the counterpressurizing gas until the pressures of the gas and the liquid is equal. A second valve is then opened allowing the liquid to flow into the bottle under the influence of gravity. When the bottle is filled the cam actuator closes the valve and the bottle is lowered away from the valve in a sequenced operation. The pressure in the neck of the bottle is then controllably released by a so-called "snift" valve and the bottle quickly capped or crowned.
While the filling valve of the Antonelli reference is useful and has been a success, nevertheless it would be desirable to further improve it. For example, the Antonelli valve in a presently popular embodiment stands sufficiently tall within the tank containing the counterpressurizing gas and the product with which the bottle is to be filled must be more than six inches deep. Accordingly, if filling machinery using these valves is sold in this country the tank is classified as a pressure vessel and must be very heavily constructed in order to meet applicable code specifications.
Accordingly, it is an object of the invention to provide a filling machine which does not require a tank of dimensions sufficiently great to be classed as a pressure vessel.
The Antonelli valve also requires an actuator external to the tank for controlling the flow of gas and thereafter of product into the bottle to be filled. See also U.S. Pat. No. 3,090,408 to Naecker.
It is an object of the invention to avoid such mechanical actuators of the valve. U.K. Patent 777,929 to Snelling controls the two valves by relative motion of the bottle with respect to the valve, thus avoiding mechanical actuators in the tank, as in Antonelli. However, Snelling still requires plural carefully controlled movements of the bottle. It would be desirable to avoid all such critical mechanical steps. Furthermore the Snelling design is of a valve too tall to fit within a non-pressure vessel sized product tank.
The Antonelli reference requires a cam to actuate the snift valve to release the pressure within the neck of the bottle after filling.
It is an object of the present invention to avoid both the snift valve and the accompanying actuator. The Snelling valve does so, but is unduly complex, as mentioned above.
The Antonelli patent places the gas and the product within the same chamber. Therefore, in order to clean the valve it must be removed from the machine as there is no way to reliably flow a detergent and water solution through all parts of the valve.
While prior art references show separate supplies of gas and product, e.g. in U.S. Pat. No. 3,478,785 to Millrich, it remains an object of the invention to provide a filling valve which can be cleaned in place.
The Antonelli valve rotates with the bottle and product tank and is controlled by a stationary actuator, so that it is operated in accordance with its position with respect to the actuator and opens, releasing product, regardless of whether or not there is a bottle in place under the valve when it is opened. Accordingly, if a bottle should break or for some reason not be present under the valve, product is lost.
It is an object of the invention to provide a valve in which absence or breakage of a container automatically prevents the valve from opening so as to preserve product. Again Snelling appears to fulfill this object, but adds undue complexity.
It is a further general object of the invention to provide a less expensive filling valve and bottle filling machine.
A further object of the invention is to provide a valve filling machine which is capable of higher speed operation than possible in the prior art.
A further object of the invention is to provide a bottle filling machine in which there are provided no external cam actuators which require some overlap of cycle timing sequences thus necessitating slower operation.
An ultimate object of the invention is to provide improved filling machine performance at reduced cost.